How to set the font color of the data labels of the doughnut chart using python-pptx?

Question

I am trying to format the doughnut chart using the below code. It's doing everything except changing the color of data labels.

d_plot = chart.plots[0]
d_plot.has_data_labels = True
for series in d_plot.series:
    values = series.values
    counter = 0
    for point in series.points:
        ddl = point.data_label
        ddl.has_text_frame = True
        ddl.text_frame.text = str("{:.0%}".format(values[counter]))
        ddl.text_frame.paragraphs[0].font.name = "calibri"
        ddl.text_frame.paragraphs[0].font.size = Pt(9)
        ddl.font.color.rgb = RGBColor(255, 0, 0)
        counter = counter + 1`

Is there a way to achieve that? Any help will highly appreciable.

Answer 1

Give this a try:

plot = chart.plots[0]
plot.has_data_labels = True
for series in plot.series:
    for point, value in zip(series.points, series.values):
        data_label = point.data_label
        data_label.has_text_frame = True
        text_frame = data_label.text_frame
        text_frame.text = str("{:.0%}".format(value))
        font = text_frame.paragraphs[0].runs[0].font
        font.name = "Calibri"
        font.size = Pt(9)
        font.color.rgb = RGBColor(255, 0, 0)

The main difference I saw was your second-to-last line:

ddl.font.color.rgb = RGBColor(255, 0, 0)

Which is looking for a font on the data-label rather than data_label.text_frame.paragraphs[0] . Once you set an attribute on the font on the paragraph it's going to override any font defined higher up. Since I don't suppose you're concerned about inheriting any font characteristics, I went ahead and set them all at the run level, which overrides anything defined higher up in the style hierarchy.

The rest is just more explicit naming, a fancier way of iterating through values and points at the same time, and avoiding repeated dereferencing, in particular using the same font for setting all the font properties.